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25 Cards in this Set
- Front
- Back
What can disrupt A/C membrane?
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-temp/humidification levels
-infectious agents -organic and inorganic dusts -gases |
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How is upper a/w condition for protection?
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-Inspired air filtered by nasal hairs & turbulent airflow.
-Impaction of larger particles(10microm) on mucus membrane. |
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What happens to air en route through conducting a/w?
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It is warmed to 37 degrees & saturated with water vapour to prevent dessication of gas exchange area.
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What triggers exercise-induced bronchospasm?
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Increase in exposure to dry air in conducting a/w with hypertonic fluid at epithelial surface activating inflammation & mediator release.
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Where are goblet cells found?
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Epithelium.
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Where do you find mucus glands?
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submucosa
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What constitutes mucus?
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High molecular weight mucin glycoproteins encoded by at least 8 genes
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What removes mucus-impacted material?
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Mucociliary escalator-sweeps mucus to the epiglottis at rate of 1-2 cm/min.
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What kind of particles settle in gas exchange region by diffusion?
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Smaller particles of 1-5 micro-m.(flushed away by pulm. circ. into syst. circ.)
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Where does the mucus sit?
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On top of the rapidly beating cilia that are surrounded by a less viscous solution(sol)
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What happens with increase in viscosity of periciliary soln?
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Decrease beat freq. and delay clearance of mucus.
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Name factors which decrease ciliary beat freq.
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Air pollutants,tobacco,smoke,local and general anesthetics,bacterial products,viral infections.
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What would cause uncoupling of cilia from mucus?
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Excessive fluid secretion
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What would cause slowing of beat due to resistance of viscous surrounds?
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Insufficient fluid secretion.
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What are the roles of surfactant proteins A & D found in mucus?
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Antibacterial-opsonin like activity.
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What is the role of complement components found in mucus?
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Opsonise and exert direct toxicity on bacteria.
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What will iron-binding pz such as lactoferrin/transferrin in mucus do?
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Bind iron to inhibit bacterial growth.
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What are defensins?
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Salt-sensitive antimicrobial peptides.(secreted by epithelium by neutrophils)
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What is the function of anitproteases found mucus?(levels increased by IL-1 & TNFaplha)
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Screen to prevent indiscriminant proteolysis by proteases released by neutrophils.
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Name some antioxidants found in mucus.
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Glutathione,vitamin E,catalase,superoxide dismutase(SOD) reduce toxicity of O2- and OH.
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Name a few diseases where mucus accumulates.
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Asthma,CF,chronic bronchitis,COPD.
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What happens when mucus accumulates?
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Forced expiration and cough ----> generate high airflow rates.
-if mucus too thick or too runny,NOT expectorated. |
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What can N-acetylcysteine do to mucus?
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Sulphydryl agent that disrupt S-S bonds in mucus and loosen mucus plugs.
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What is the function of cough?
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Removes obstruction from large a/w + removes mucus from a/w.
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Describe cough.
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Large inspiration and explosive expiration v/s narrowed a/w and a closed UA----> sufficient airflow velocity to remove firmly lodged material.
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